The objective of the project is to continue the investigation of the visual capacities of human infants, by means of behavioral (psychophysical) techniques. Forced-choice preferential looking studies of both color vision and acuity (including frequency response functions) will be continued, with infants below six months of age. In the case of color vision, the studies will include both presumptively normal and presumptively dichromatic infants. In the case of acuity and FRF's, both normal and presumptively astigmatic infants will be studied. In addition to the preferential looking studies, the development of techniques employing the sucking response will also be continued; and this technique will be used for additional studies of color vision and the FRF.